Sound-absorbent railway track



N0V- 7. 1967 F. PAASCHE ETAL 3,351,283

SOUND-ABSORBENT RAILWAY TRACK Filed May 1S, 1965 2 Sheets-Sheet 1 1I l F/6./. lb y /I /HIO lo@ 9A Ilma 1 slum .o L 2 Nov. 7, 1967 F. PAAscHE ETAL 3,351,283

SOUND-ABSORBENT RAILWAY TRACK Filed May 1S, 1965 2 Sheets-Sheet 2 United States Patent O 3,351,283 SOUND-ABSORBENT RAILWAY TRACK Fritz Paasche, Cologne-Nippes, Carl-Heinz Zipf, Cologne-Muehlheim, and Robert Mller, Cologne- Bayenthal, Germany, assignors to Franz Clouth Rheinische Gummiwarenfahrik Aktiengesellschaft,

Cologne-Nippes, Germany Filed May 18, 1965, Ser. No. 456,679 1t) Claims. (Cl. 23S-283) ABSTRACT OF THE DISCLOSURE A rail is provided with a flange. A support is disposed below the flange spaced therefrom. A rigid tie plate is located between the flange and the support. A layer of sound-absorbent elastomeric material is located between the support and the tie plate, and connecting means connects the flange with the support and extends through the tie plate and through the layer of elastomeric material.

The present invention relates to railway tracks in general, and more particularly to a railway track with improved sound-absorbent characteristics.

It is well known that the rails and other parts of a railway track produce considerable noise and that such noise is due to vibration which is caused by a vehicle or by a train of vehicles traveling along the heads of rails. Proposals to reduce such noise include utilization of rubber layers or pads between the flanges of rails and the cross ties and/or the provision of similar pads between the flanges and the spikes or clamps which secure the rails to the cross ties. A serious drawback of such constructions is that the pads between the spikes -and the anges must be subjected to considerable pre- -liminary compression in order to prevent shifting of rails. The ability of rubber layers to reduce noise decreases with increasing compression and with a reduction in surface area. Since the flanges of standard rails have a definite constant width, the area of rubber pads can only be increased in the longitudinal direction of -the rails which, of course, adds considerably to the overall length of connections between the flanges and the cross ties. In other words, the surface area of pads between the flanges and the spikes must have a certain minimum area if such pads are to be effective in reducing noise.

Accordingly, it is an important object of the present invention to provide a railway track wherein the layers of sound-absorbent material are distributed and mounted in such a way that they must undergo a minimum of initial compression and will thus bring about a considerable reduction or complete elimination of noise which normally develops in response to vibration caused by a passing vehicle.

Another object of the invention is to provide a railway track wherein the sound-absorbent material is dimensioned and installed in such a way that its sound deadening characteristics improve with increased load upon the rails.

A further object of the invention is to provide a railway track wherein the sound-absorbent material is installed in such a way that each connection between a rail and its supporting structure occupies very little space without in any way affecting the sound deadening characteristics of such material.

An additional object of the invention is to provide improved sound-absorbent anchoring devices for the spikes or clamps which secure the anges of steel rails to cross ties and to construct the anchoring devices in such a way that they may be readily installed in existing railway tracks without in any way affecting the reliability of connections between the spikes or clamps and the flanges of rails.

Still another object of the invention is to provide a railway track which embodies the improved sound-'absorbent structure and which may be used indoors or outdoors as well as for standard or narrow gauge Vehicles.

A concomitant object of the invention is to provide a railway track wherein the elements which constitute the sound deadening structure are congurated in such a way that the ratio of their surface area to overall dimensions is much higher than in heretofore known soundabsorbent structures and that such elements may be fully concealed and protected from dust, moisture and other undesirable influences.

Briefly stated, one feature of our invention resides in the provision of a railway track which comprises a rail having ya flange, a rigid support which may constitute a cross tie or a portion of ballast consisting of concrete or the like, a transversely extending rigid tie -plate located between the support and the rail and preferably abutting directly against the underside of the flange, a layer or pad of sound-absorbent elastomeric material interposed between the tie plate and the support, clamping means for pressing the flange against the tie plate, and an arrangement for pressing the tie plate against the layer of elastomeric material and for securing the tie plate to the support. This arrangement comprises a pair of substantially frustoconical anchoring devices which may be located at a level above the tie plate at the opposite sides of the flange, or each thereof may be embedded in the material of the support. Each anchoring device comprises a hollow core consisting of metal or another rigid material and an annular (preferably frustoconical) filler of sound-absorbent elastomeric material which surrounds the core. The aforementioned arrangement further comprises a pair of bolts each of which has a head received in the core of the respective anchoring device and a stem extending through bores provided in the respective anchoring devices, in the tie plate and in the layer of elastomeric material, and a pair of nuts each of which meshes with one of the stems. Such nuts may be embedded in the material of the support or each thereof may engage a plate-like clamping member, depending upon whether the anchoring devices are embedded in the support or are located at a level above the tie plate.

The mounting of the anchoring devices and of the bolts and nuts is such that the pressure upon the normally deformed annular fillers decreases when the adjacent portion of the rail carries a load so that the ability of such fillers to absorb noise improves at the very moment when the track is likely to produce a maximum of noise.

The novel features which are considered as characteristie of the invention are set forth in particular in the appended claims. The improved railway track itself, however, both as to its construction and the mode of assembling the same, together with additional features and ad- 'vantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a transverse vertical section through a portion of a railway track which is constructed and assembled in accordance with a rst embodiment of our invention;

FIG. 2 is a top plan view as seen in the direction of arrow II in FIG. 1; and

FIG. 3 is a transverse vertical section through a portion of a modified railway track.

Referring first to FIG. l, there is shown a T-rail 1 consisting of rolled steel and having -a flange or base 1a which rests directly on a transversely extending steel tie plate 2. The tie plate 2 is located above a support here shown Vas a cross tie 4 which consists of concrete. A layer or pad 3 of rubber or another sound-absorbent elastomeric material is interposed between the underside of the tie plate 2 and the upper side of the cross tie 4. Two frustoconical anchoring devices A, B each of which consists in part of rubber or another sound-absorbent elastomeric material are embedded in the Amaterial of the cross tie 4 at the opposite sides of the rail 1. Such anchoring devices may be placed into a mold in which the cross tie 4 is to be formed, i.e., prior to pouring of concrete, or they may be inserted from below into downwardly di verging frustoconical recesses 4d provided in a prefabricated cross tie and are secured thereto by a suitable adhesive or the like.

Each of these anchoring devices comprises a hollow frustoconical shell 5 consisting of metal and having a bottom wall 5a, a rigid hollow frustoconical core 6 which is received with clearance in the respective shell 5 and may but need not extend to the bottom wall 5a, and a hollow frustoconical sound-absorbent body or tiller 7 which consists of rubber or another sound-absorbent elastomeric material and iills the space between the internal surface of the shell 5 and the peripheral surface of the core 6. Each filler 7 is vulcanized to the adjoining surfaces of the respective shell 5 and core 6.

The cross tie or support 4 is accommodated in a recess 8a provided in a ballast 8 which spreads the load of the railroad vehicle or vehicles and which may consist of concrete, wood, broken stone or any other suitable material whose selection will depend on many factors, for example, whether the railway track is used indoors or outdoors. Prior to insertion into the recess 8a, the cross tie 4 is combined with the anchoring devices A and B so that the parts A, B and 4 :form a rigid unit. If the ballast 8 consists of concrete, the gaps around the cross tie 4 may be filled with concrete to make sure that the cross tie is securely embedded in the material of the ballast.

It will be noted that each of the anchoring devices A, B is provided with a vertically extending axial through bore 6a, 7a which passes through the core 6 and filler 7 and registers with a bore 3a in the layer 3 and with a bore 2a in the tie plate 2. Also, the cavity 6b of each core 6 accommodates the head 9a of a male coupling element here shown as a bolt 9 which forms part of a composite fastener serving to secure the flange 1a to the tie plate 2 and to secure the tie plate to the cross tie 4. The stem 9b of each bolt 9 extends through the respective bores 6a, 7a, 3a, 2a, and the threaded portions of these bolts mesh with female coupling elements in the form of nuts 9A which bear against the upper sides of apertured clamping plates 10. Each clamping plate 10 has a projection or nose 10a which overlies and bears against the adjoining portion of the ange 1a. The stems 9b of the bolts 9 extend through the apertures of and upwardly ybeyond the clamping plates 10. It will be seen that each of the two fasteners shown in FIG. l comprises a bolt 9, a nut 9A, and a clamping plate 10. Washers 10a are interposed between the clamping plates 10 and the tie plate 2, and such Washers may consist of metal or an elastically deformable sound-absorbent material.

The nuts 9A are driven home with a force which sufvtices to prevent shifting of the rail 1 and also to subject the anchoring devices A, B and the layer or pad 3 to at least some initial stresses. When the nuts 9A are driven home, the heads 9a of the bolts 9 are drawn upwardly to eifect some displacement of the cores 6 and to thereby deform the llers 7. At the same time, the layer 3 is compressed between the cross tie 4 and tie plate 2. The surface area of the layer 3 equals that of the tie plate 2.

Due to the fact that the anchoring devices A and B resemble conical frusta, the height and the diameter of each filler 7 and of each layer 3 may be selected with a view to take into consideration the stresses which arise when one or more vehicles travel on the track which includes the rail 1, particularly the surface-to-surface pressure between the layer 3 and the parts 2, 4 as well as the shearing stresses upon the fillers 7 Another important advantage of our improved track is seen in that, whenever a vehicle travels on the head 1b of the rail 1, i.e., at

the time when the track will tend to produce noise, the shearing and compressive stresses upon the fillers 7 are reduced because the heads 9a of the bolts 9 will move downwardly and will allow the fillers to assume or to move closer to their unstressed conditions. Such reduction or deformation of the fillers 7 improves the sounddeadening characteristics of the anchoring devices A and B.

FIG. 2 shows a pair of cross ties 4 each of which carries two fasteners including bolts 9, nuts 9a and clamping plates 10.

In heretofore known railway tracks, the sound absorbing structure includes pads of elastomeric material which are inserted between the flange and the clamping plates. If the pads are small, they will absorb very little noise, especially if they are subjected to rather high initial compression. On the other hand, if the pads are rather large, they must extend in the longitudinal direction of the rail and must be compressed by large clamping plates. In accordance with our present invention, such conventional pads are replaced by the fillers 7 which are fully concealed and protected -from rain, dust or other corrosive influences. Also, the dimensions of the clamping plates 10 are not dependent on the dimensions of the fillers 7 because such llers need not be inserted between the noses 10a and the flange 1a. The area of contact `between the fillers 7 land the parts 5, 6 is very large and, furthermore, the compression of llers 7 decreases when the rail 1 carries a load so that the ability of such llers to absorb noise improves at the very time when the noise is generated by a passing conveyance.

The layer or pad 3 is protected from corrosive intluence of rain or dust because this layer is placed between the plate 2 and the cross tie 4. Such mounting also prevents overstressing of the layer 3 because the stresses are not localized but are distributed unifomly in each zone of the layer. In many heretofore known railway tracks, the flange of the rail rests directly on the layer of elastomeric material and, therefore, such material is not subjected to uniform compression. Also, such conventional tracks comprise sound-absorbent layers whose width does not exceed the width of the flanges whereas the layer 3 shown in FIG. l can have the same area as the tie plate 2. The length of the tie plate 2 may exceed several times the width of the ange 1a so that the layer 3 will absorb much more noise than a pad whose width does not exceed the width of the flange.

FIG 3 illustrates a portion of modified track which comprises a pair of differently mounted anchoring devices D, E. Such anchoring devices may be installed in an existing track to reduce noise. The ange 1a of the rail 1 rests Idirectly on the central portion of tie plate 2' which, in turn, rests on the upper side of the soundabsorbent layer or pad 3 consisting of rubber or the like. The track of FIG. 3 does not have a distinct cross tie because the material 15 which supports the elastomeric layer 3 forms an integral part of a concrete ballast or oor 8.

The ange 1a is received between two projections 2b', 2c of the tie plate 2 so that it is held against lateral movement. The clamping plates 10 are replaced by two looped clamping members 17 which consists of spring steel and each of which comprises an end portion 17a extending in the longitudinal direction of the rail 1 and bearing against the adjoining portion of the ange 1a. The other end portions 17b of the clamping members 17 are received in blind bores 2d provided in the projections 2b', 2c'.

Each of the two anchoring devices D, E shown in FIG. 3 comprises a thin metallic shell 11, a metallic core 12 and a ller 13 of rubber or the like. The smaller-diameter end portion of each shell 11 extends into a shallow circular depression 2e provided in the upper side of the tie plate 2'.

Each of the two fasteners shown in FIG. 3 comprises an elongated bolt 14 having a head 14a which is accommodated in the cavity 12b of the respective core 12 and a stern 14b which extends through aligned bores 12a, 13a, 2a', 3a' and meshes with an elongated sleeve-like nut 16 which is securely embedded in the portion 15 of the ballast 8'. The bolts 14 are driven home with a force which sutces to subject the layer 3' and the fillers 13 to requisite initial compression. When a vehicle travels along the head 1b of the rail 1, the tie plate 2 bears against and effects stronger but uniform compression of the layer 3. At the same time, the pressure lbetween the tie plate 2 and the shells 11 is reduced so that the fillers 13 are subjected to lesser deforming stresses which contributes to superior sound deadening action of the anchoring devices D and E.

The nuts 1b may be permanently embedded in the material of the ballast 8 which latter constitutes a support for the tie plate 2'.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of the equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is:

1. In a railway track, a rail having a flange; a rigid support located below said flange and having a pair of conical recesses whose diameters decrease in a direction downwardly from the upper side of said support, said recesses being located at the opposite sides of said flange; a rigid transversely extending tie plate disposed between said rail and said support and directly abutting against said flange; a layer of sound-absorbent elastomeric material interposed between said tie plate and said support; a pair of anchoring devices each comprising a hollow frustoconical shell fitted into one of said recesses; a hollow frustoconcial core received with clearance in the respective shell, and a frustoconical filler of sound-absorbent elastomeric material received between each shell and the respective core; a pair of clamping members disposed at the opposite side of said ange and each having a first portion overlying said iiange and a second portion provided with an aperture registering with vertical bores extending through said tie plate, said layer and axially through one of said anchoring devices; and a pair of fasteners each comprising a bolt having a head received in one of said cores and a stem extending upwardly through the respective bore and through the aperture of the respective clamping member, and a nut meshing with the respective stern and located above the corresponding clamping member.

2. In a railway track, a rail having a flange; a rigid support located below said flange; a pair of nuts embedded in said support at the opposite sides of said ange; a transversely extending rigid tie plate located between said rail and said support and directly abutting against the underside of said flange; a layer of sound-absorbent elastomeric material interposed between said tie plate and said support, said tie plate and said layer having pairs of bores each of which is coaxial with one of said nuts; a pair of clamping members each secured to said tie plate and each engaging a portion of said ange, said clamping members being located at the opposite sides of said rail; a pair of frustoconical anchoring devices each including a frustoconical shell having a smaller-diameter end portion abutting against the upper side of said tie plate, a hollow frustoconical core received with clearance in the respective shell, and a frustoconical filler of sound-absorbent 6 elastomeric material received between each shell and the respective core, each of said anchoring devices having an axial bore registering with one bore of said tie plate; and a pair of bolts each having a head received in one of said cores and a stem extending through the bore of the respective anchoring device, through the corresponding 'bores in said tie plate and said layer, and into mesh with the respective nut to press said tie plate against said Vlayer and to simultaneously deform the respective filler.

3. In a railway track, a rail having a ange; a support located below said ange; a rigid tie plate located between said flange and said support; clamping means engaging a portion of said ange; and means for securing said clamping means and said tie plate to said support, comprising a fastener including a male coupling element extending through a bore provided in said tie plate and into said support, said male coupling element having a head portion located at one side of said tie plate and said fastener further including a female portion meshing with said male coupling element and located at the other side of said tie plate, one of said portions being received in said support, and anchoring means comprising a rigid shell, a hollow core received with clearance in said shell and surrounding said head portion, and an annular filler of elastomeric sound-absorbent material interposed between said shell and said core and surrounding the latter.

4. In a railway track, an anchoring device comprising a rigid shell; a rigid hollow core received with clearance in said shell, and an annular filler of sound-absorbent elastomeric material interposed between said core and said shell; and fastener means including a bolt having a head received in said core and a stern extending through registering bores in said rigid shell and said rigid hollow core.

5. In a railway track, an anchoring device comprising a rigid hollow frustoconical shell; a rigid hollow `frustoconical core received with clearance in said shell, and a frustoconical iller of sound-absorbent elastomeric material received between said core and said shell; and fastener means including a bolt having a head received in said core and a stem extending from said head through and beyond an axial bore provided in said anchoring device, the diameter of said anchoring device decreasing in a direction toward the free end of said stem.

6. In a railway track, an anchoring device comprising a rigid shell; a rigid hollow core -received with clearance in said shell, and an annular filler of sound-absorbent elasv tomeric material interposed between and permanently secured to said core and said shell; and fastener means including a bolt having a head received in said core and a stem extending through registering bores provided in said rigid shell and said rigid hollow core.

7. In a railway track, an anchoring device comprising a rigid hollow frustoconical shell; a rigid hollow frustoconical core received with clearance in said shell, and a frustoconical iiller of sound-absorbent elastomeric material received between and vulcanized to said core and to said shell; and fastener means including a bolt having a head received in said rigid hollow frustoconical core and a stem extending from said head through axial bores provided in said rigid hollow frustoconical shell and said rigid hollow frustoconical core, the diameter of said rigid hollow frustoconical shell decreasing in a direction toward the free end of said stem.

8. In a railway track, a T-rail having a iiange constituting the lower end portion thereof; a support consisting of concrete and having an upper side spaced from said iiange; a rigid tie plate located between said rail and said support; a pad of sound-absorbent elastomeric material interposed between the upper side of said support and said tie plate; clamping means securing said iiange to said tie plate; and coupling means securing said tie plate to said support, said coupling means comprising an anchoring device having an annular portion consisting of sound-absorbent elastomeric material, and a fastener having a first portion surrounded by said annular portion, a second portion extending through bores provided in said tie plate and said layer, and a third portion extending into said support.

9. A structure as set forth in claim 8, wherein said anchoring device is located above said tie plate and said fastener includes a bolt and a nut meshing with said bolt and embedded in said support.

10. A structure as set forth in claim 8, wherein said anchoring device is embedded in said support and said fastener comprises a bolt extending through an aperture provided in said clamping means and a nut meshing wit said bolt and abutting from above against said clamping means, said clamping means comprising .a portion overlying the flange of said rail.

8` References Cited UNTED STATES PATENTS 2,291,611 8/1942 Dooling 23S- 283 5 FOREIGN PATENTS 1,151,236 8/1957 France.

865,119 4/ 1961 Great Britain.

83,688 5/1954 Norway.

10 ARTHUR L. LA POINT, Primary Examiner.

R. A. BERTSCH, Assistant Examiner. 

1. IN A RAILWAY TRACK, A RAIL HAVING A FLANGE; A RIGID SUPPORT LOCATED BELOW SAID FLANGE AND HAVING A PAIR OF CONICAL RECESSES WHOSE DIAMETERS DECREASE IN A DIRECTION DOWNWARDLY FROM THE UPPER SIDE OF SAID SUPPORT, SAID RECESSES BEING LOCATED AT THE OPPOSITE SIDES OF SAID FLANGE; A RIGID TRANSVERSELY EXTENDING TIE PLATE DISPOSED BETWEEN SAID RAIL AND SAID SUPPORT AND DIRECTLY ABUTTING AGAINST SAID FLANGE; A LAYER OF SOUND-ABSORBENT ELASTOMERIC MATERIAL INTERPOSED BETWEEN SAID TIE PLATE AND SAID SUPPORT; A PAIR OF ANCHORING DEVICES EACH COMPRISING A HOLLOW FRUSTOCONICAL SHELL FITTED INTO ONE OF SAID RECESSES; A HOLLOW FRUSTOCONICAL CORE RECEIVED WITH CLEARANCE IN THE RESPECTIVE SHELL, AND A FRUSTOCONICAL FILLER OF SOUND-ABSORBENT ELASTOMERIC MATERIAL RECEIVED BETWEEN EACH SHELL AND THE RESPECTIVE CORE; A PAIR OF CLAMPING MEMBERS DISPOSED AT THE OPPOSITE SIDE OF SAID FLANGE AND EACH HAVING A FIRST PORTION OVERLYING SAID FLANGE AND A SECOND PORTION PROVIDED WITH AN APERTURE REGISTERING WITH VERTICAL BORES EXTENDING THROUGH SAID TIE PLATE, SAID LAYER AND AXIALLY THROUGH ONE OF SAID ANCHORING DEVICES; AND A PAIR OF FASTENERS EACH COMPRISING A BOLT HAVING A HEAD RECEIVED IN ONE OF SAID CORES AND A STEM EXTENDING UPWARDLY THROUGH THE RESPECTIVE BORE AND THROUGH THE APERTURE OF THE RESPECTIVE CLAMPING MEMBER, AND A NUT MESHING WITH THE RESPECTIVE STEM AND LOCATED ABOVE THE CORRESPONDING CLAMPING MEMBER. 